Sparks Electrical News April 2024

CABLES AND CABLE ACCESSORIES

12

Why utilities and the industry should consider medium-voltage XLPE cables over PILC cables P aper-insulated lead cables (PILC) have been in use for more than 100 years in medium voltage (MV) applications ranging from impermeable, XLPE is also available in cost-effective water blocking formats for both longitudinal and radial water blocking upon request. Aberdare Cables is one such manufacturer that can adapt products to suit client needs.

6.6KV up to 36KV, and on the odd occasion they are used in high-voltage systems as well. PILC has been preferred over the years due its high dielectric strength, low dissipation factor, relatively low dielectric loss, low sensitivity to direct current (DC) testing, and proven reliability. PILC has become less popular over the years though, with it being replaced by cross linked polyethylene (XLPE) due to factors impacting its cost-effective use. Many cable manufactures around the world have discontinued PILC due to the related reduction in demand as a result. Electrical engineer Donemore Torerwa, who is General Manager: Product Development & Applications at leading manufacturer Aberdare Cables, says, “XLPE as an insulating medium has a lower dielectric constant, lower dielectric loss, high dielectric strength, and operates at higher temperatures. This allows the cable to be more efficient when carrying far more current than the same size PILC version. Generally, XLPE is preferred by customers for factors to do with ease of use, efficiency, less complexity when it comes to using accessories and more.” Below are a few reasons why XLPE is chosen over PILC for MV cable insulation: • XLPE has a higher current rating compared to the same size PILC cable due to XLPE having a higher operating temperature. • Installation, maintenance and repair processes are more complex, intensive, timeous, and costly for the PILC version, which makes XPLE the better business option. • Accessories such as jointing and termination kits are not easy to locate as many factories worldwide have discontinued paper cable production. • There is a significant skills shortage for splicing, jointing and termination of PILC which as a result leads to an increase in the number of PILC failures due to suspected poor workmanship. • Although PILC has been somewhat better at providing radial water blocking properties with the lead sheath, which is completely

• XLPE cables are more flexible compared to PILC cables that increase in rigidity as the size of the cable increases. XLPE can therefore be used easily where shorter bending radius is required. • Paper-insulated lead cable is oil impregnated with mineral oil or PIB and has a lead sheath (heavy metal) that increases the risk of environmental contamination. XLPE is favoured where an environmental analysis is considered as a key consideration for design decision. “Aberdare Cables offers XLPE cables up to 132KV for customers across Africa and around the globe,” says Torerwa. “For voltages higher than 132KV, XLPE cables can also be provided by Aberdare Cables through its parent company Hengtong Group in China.”

Cu-flex busbar from Referro Systems introduces new cabling options D istribution company Referro Systems is continuing its busy

or movement could cause rigid connections to fail. Cu-flex busbars also offer flexibility to accommodate changes or additions to the systems,” says Referro. Industrial machinery: Flexible copper busbars like the Cu-Flex system can be used for power transmission, control systems and motor connections. Moveable equipment: These busbars are perfect for use in electrical systems where weight savings and flexibility are essential, such as in aircraft wiring. Power distribution: Busbars can be used to connect large electrical equipment, such as generators and substations, as well as smaller equipment. Power electronics: In power electronic devices such as inverters and rectifiers, Cu Flex busbars can be used to connect semiconductor devices, capacitors and other components to ensure system integrity. Reliable earthing: Cu-Flex busbars can be used for grounding and connecting various electrical components, giving operators peace of mind that their electrical system is safe to use without the threat of failure and injury to staff. Renewable energy: Wind turbines and solar inverters can benefit from the flexible copper bars if they are utilised to interconnect components and carry high currents generated by these renewable energy sources Cu-Flex busbars have been tested, approved and certified under various authorities such as DEKRA (Deutsche Kraftfahrzeug Überwachungs-Verein) and DNV (Det Norske Veritas). Cu-Flex technology is also UL (Underwriters Laboratories Inc) recognised in category Component – Panel Board & Switchboard Accessories.

start to 2024 by introducing to the South African market the Cu-Flex copper busbar from Danish electrical brand Cubic. What sets this product apart is that it is flexible, which makes system design more flexible itself. By definition, electrical busbars are metallic strips or bars inside switchgear, panel boards, or other electrical distribution equipment. It facilitates local high-current power distribution and avoids problems when joining two cables into one since it acts as a junction where the incoming power and outgoing power meet. Cu-Flex flexible copper busbars are manufactured from strands of copper wires that are woven into a flexible busbar. “Using a proprietary technique, the ends of the busbar are forged into a solid unit,” says Referro, adding, “The insulated and flexible busbar provides time saving and maintenance-free connection contact surfaces for motor control centres, switchboards or industrial control panels.” The busbars are supplied ready for use without users having to shorten and strip the wires, make holes, or complicated bends. The Cu-Flex busbars add new options, opportunities and advantages to electrical systems, and can be used for several applications including: Battery systems: In large scale energy storage systems or electric vehicles, Cu flex busbars can be used to connect battery cells or modules. Electrical connections: Cu-Flex busbars provide a reliable, low-resistance connection between electrical components such as transformers, circuit breakers and other busbars. “They are particularly useful where vibrations, thermal expansion

Enquiries: www.aberdare.co.za

Enquiries: www.referro.co.za

SPARKS ELECTRICAL NEWS

SPARKS ELECTRICAL NEWS

APRIL 2024

APRIL 2024